The positive effect of circumcision on HIV transmission rates in resource-poor countries has made headlines over the past year. Within the United States, however, it is not protective for black and Latino men who have sex with men (MSM), according to new data presented at the 2007 National HIV Prevention Conference in Atlanta.

Two recent African studies found that HIV-negative men who underwent circumcision were 50 to 60 percent less likely to become infected from their female partners than men who remained uncircumcised. To determine whether circumcision status would have the same impact on MSM of color in the U.S., Gregorio Millett, MPH, from the Centers for Disease Control (CDC) in Atlanta and his colleagues conducted an observational study among black and Latino MSM in New York City, Los Angeles and Philadelphia.

Millett’s team enrolled 1,154 black and 1,091 Latino MSM in the three cities. The men were asked to complete a computer-assisted survey regarding their risk behaviors and circumcision status and to be tested for HIV. The researchers focused on black and Latino MSM because of research showing them to be disproportionately affected by HIV compared with white MSM. The survey revealed that circumcision was much more common among black men, 74 percent of whom were circumcised, compared with Latino men, of whom only 33 percent were circumcised.

Overall, the study found no statistically significant association between circumcision status and HIV diagnosis. Further analysis showed that among black MSM, circumcision was not associated with HIV status regardless of whether the men reported sex exclusively with other men or with both men and women. This analysis was only possible with black MSM, as too few Latino MSM reported sex with female partners.

Of the 925 black and Latino MSM who reported being HIV negative on their last test result before entering the study, 61 (6.6 percent) were HIV positive after study enrollment. Circumcision status had no effect on the new diagnosis.

Of a much smaller group of men, 320 in all, who reported having only insertive unprotected anal intercourse with other men, circumcision status again showed no protective effect.